Arc-controlling means for vapor-converters.



s. W. FARNSWORTH.

ARC CONTROLLING MEANS FOR VAPOR CONVERTERS.

APPLICATION FILED AUG-6.1915.

Partented Aug. 13, 1913.

I \A m INVENTOR Ju /7g W Fa'rMM/f/I WITNESSES:

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Specification of Letters .Patent.

Patented Au 13, 1918 Application filed August 6 1915. S eria1No. -i4,001.

To all whom it may concern:

lBe it known that I, SIDNEY-W. FARNswears, a citizen of the United States, and a.

resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have in-l to provide means of the character mentioned that shall maintain said are in a stable condition upon either the anode or the cathode or upon electrodes of both polarities, if so desired. I

In the accompanying drawing, Figure 1 is a sideview, artially in section and partially in elevation, of a vacuum-type converter embodying one form of my'invention; and Fig. 2 is a top view, partially in plan "and partially in section, of a portion of the converter shown in Fig.1, illustrating more clearly the structure thereof.

In the operation of vacuum-type converters, there is frequently a marked tendency for the power are to move about in an erratic manner under the influence of obscurev forces, such, for example, as thermal influences and unbalanced gas and vapor pressures and conductivities. In the ordinary anode, it is substantially impossible to libcrate all the occluded gases in the process of treating-out, said process being effective only in the lower and ,more exposed portions ofthe electrode. Any wandering of the are away from suchtreated portions to portions.

sertion of any solid shielding body into the cathode for the purpose of restricting this action may be harmful because the arc may operate in immediate proximity thereto,

liberating gases therefrom and producing;

other undesirable results.

By my invention, I avail myself of the well-known phenomenon of the action of a magnetic field on a current-carrying arc in accordance with Flemings left-hand motor rule and I so disposemagnetic fields adjacent to the'electrodes of a vapor converter as to effectually minimize all of the abovedescribed harmful effects. A feature of my invention which is especially' worthy of note is that I may obtain the desired magnetic fields by the suitable shaping of the current leads of the converter, under. certain conditions even disposing said shaped current leads within the container itself.

Referrin to Fig. '1 of the accompanying drawings or a more detailed understanding of my invention, I show the container of a vapor converter at Z, said converter being equip ed with a main anode 8 and with a catho e 10, preferably composed of vaporizable reconstructing material, such, for example, as mercury or suitable amalg'ams.

Current is supplied to the, anode 8 through an anode lead and stem sealed into the cover of the container 7 in the usual manner. The

cathode 10 may be insulated from the container 7 or not, as is desired, but current is supplied thereto through a loop or bight 20,

- preferably composed of seamless conducting tubing, having its right-hand branch 22 disposed to form an arc-controlling helix 23 about the'anode 8. 'Said branch 22 is then I coiled in the form of a circular helix 24:, disposed slightly above the surface of. the

cathode, before joining the left-hand branch 25. Contact is made with the material of the cathode 10 in a loop 26 at the foot of the branch 25 so that load current from the cathode flows entirely through the coils 24 and '23 before reaching the cathode lead-28.

- In'o'peration, let it be assumed that an arc anode 8 and the'central portion of the cathode 10 by any suitable ,means, such, for ex ample, as a keep-alive circuit 27 The current flowing from the cathode 10 through the solenoids 23 and 24 produces a-toroidalshaped bundle of. magnetic flux surrounding the active portions of both thea'node and the cathode. Said coils are wound and connected insuch manner that, if'the are approaches electrode, there is developed a force, in ac cordance with Flemings left-hand'motor '90 is initiated between the lower portion of the 10o either of said flux bundles, attempting to flow from or to .anundesired portion of an r .and from reaching and running u the wall of the container 7 adjacent the sur ace of the.

cathode 10.

I have illustrated my ivention as embodled in a converterof the well known mercuryvapor type wherein the current flow has the form of an are, but it is obvious that said invention is susceptibleof application to other whether oper or at greater.

I desireit to be understood that said term isnot used in-a limiting sense but asindicative of, and referring to, any andall forms of current flow between electrodes.v

7 While I- have shown my invention in its preferred form, it will be obvious to .those skilled in the art that it is susceptible of various minor changes and modifications without departing. from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or are specifically set forth in the appended claims.

- \I claim as my invention:

1. The combination with tus embodying means for producmg an are between two electrodes, of a solenold bent into the form of a ring and disposed adjacent to one of said electrodes so that said arc traversessa-id ring, and means for producing current flow through said solenoid having such direction, with respect to the direction of said arc, as to maintain said are upon a predetermined portion of said electrode.

2. Ina vacuum-type converter, the combination with an anode provided with an arcemitting surface which has been rendered substantially" free from occluded gases, of means for producing an are from said arc-' emitting surface, 'a solenoid bent to form a toroid and mounted adjacent to said areemitting surface, said toroid encirclin said are and having its plane disposed su stanelectric apparatially normal thereto, and'means for energizmg said solenoid, whereby magnetic flux is -.by the load current of said converter.

4. 'In a vacuum-type converter, the combination withan anode, of a cathode, means for producing an arc therebetween, and means for producing a fixed toroidal-shaped bundle of magnetic flux adjacent, and parallel, to the surface of said cathode and surroundinlg said arc, the lines of said field individua y surrounding said arc, whereby the zone of impact of said are upon said cathode is defined.

5. In a vacuum-type converter,the combination with an anode, of a cathode, means for reducing an arc therebetween, a solenoid cut into the form of a torus disposed adjacent and parallel to the surface of said cathode so as to encircle said are and means for energizing said solenoid by the lead current of said converter.

6. In a vacuum-type converter system, the combination with an evacuated container, of an anode, a cathode, current leads thereto,

. and means for producing current flow in said leads and between said electrodes, a portion of the cathode I lead being disposed within said container and being formed into a toroidal-shaped solenoid, adjacent and substantially parallel to the arc-receiving surface of said cathode, whereby the zone of arc-impact of said cathode is defined.

In testimony whereof, I have hereunto subscribed my name this 24th day of July 1915.

SIDNEY W. FARNSWORTH. 

